cext: fix memory leak in phases computation Without this a buffer whose size in bytes is the number of changesets in the repository is leaked each time the repository is opened and changeset phases are computed. Impact: the current code in hgwebdir creates a new `localrepository` instance for each HTTP request. Since any pull or push is made of several requests, a team of 100 people can easily produce thousands of such requests per day. Being a low-level malloc, this leak can't be seen with the gc module and tools relying on that, but was spotted by valgrind immediately. Reproduction ------------ for i in range(cl_args.iterations): repo = hg.repository(baseui, repo_path) rev = repo.revs(rev).first() ctx = repo[rev] del ctx del repo # avoid any pollution by other type of leak # (that should be fixed in 5.8) repoview._filteredrepotypes.clear() gc.collect() Measurements ------------ Resident Set Size (RSS), taken on a clone of mozilla-central for performance analysis (440 000 changesets). before: 5.8+hg19.5ac0f2a8ba72 1000 iterations: 1606MB 5.8+hg19.5ac0f2a8ba72 10000 iterations: 5723MB after: 5.8+hg20.e2084d39e145 1000 iterations: 555MB 5.8+hg20.e2084d39e145 10000 iterations: 555MB (double checked, not a copy/paste error) (e2084d39e14 is the present changeset, before amendment of the message to add the measurements)

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#!/usr/bin/env python3

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# like ls -l, but do not print date, user, or non-common mode bit, to avoid

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# using globs in tests.

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from __future__ import absolute_import, print_function

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import os

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import stat

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import sys

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def modestr(st):

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    mode = st.st_mode

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    result = ''

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    if mode & stat.S_IFDIR:

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        result += 'd'

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    else:

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        result += '-'

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    for owner in ['USR', 'GRP', 'OTH']:

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        for action in ['R', 'W', 'X']:

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            if mode & getattr(stat, 'S_I%s%s' % (action, owner)):

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                result += action.lower()

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            else:

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                result += '-'

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    return result

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def sizestr(st):

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    if st.st_mode & stat.S_IFREG:

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        return '%7d' % st.st_size

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    else:

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        # do not show size for non regular files

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        return ' ' * 7

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os.chdir((sys.argv[1:] + ['.'])[0])

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for name in sorted(os.listdir('.')):

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    st = os.stat(name)

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    print('%s %s %s' % (modestr(st), sizestr(st), name))